1. Technical Field
The present invention relates to an illuminator and a projector.
2. Related Art
A projector is an apparatus in which a light modulator modulates light outputted from a light source section in accordance with image information and a projection lens enlarges and projects the resultant image. In recent years, as a light source in an illuminator used in such a projector, a semiconductor laser (LD) or any other laser light source that produces high-luminance, high-intensity light has received attention.
To achieve a projector including an illuminator formed of such a laser light source, there is a known technology using a diffractive optical element to reduce the degree of interference fringes (see JP-A-2012-9872, for example).
In the illuminator described above, however, any variation in the position of the mounted laser light source or collimator lens undesirably shifts the direction of the principal ray of light incident from the laser light source on the diffractive optical element. A region illuminated with the light therefore greatly shifts, resulting in a problem of decrease in illumination efficiency.